Based on density functional theory combined with non-equilibrium Green’s function method, we investigate the thermoelectric transport properties of zigzag-edged graphene nanoribbons (ZGNRs) co-doped by two BN pairs at one edge. By applying the co-doping scheme of BN pairs instead of single B and N atoms as reported in literature, the energy of the quasi-bound states gets very close to the Fermi level. Due to the back scattering from the quasi-bound states, transmission valleys appear around the Fermi level, which results in a large transmission slope and Seebeck thermopower for both spin channels. Interestingly, the signs of the Seebeck thermopower of the two spin channels are opposite and the magnitudes are nearly equal, which can be utilized for generating pure spin current with a thermal gradient. More importantly, the thermal spin current is robust against the change of the distance between the two BN pairs and the doping configuration. These findings suggest a fascinating s...

中文翻译：

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通过热梯度在锯齿形石墨烯纳米带中产生纯自旋电流：BN对边缘掺杂的影响

基于密度泛函理论和非平衡格林函数方法，我们研究了在一条边上由两个BN对共掺杂的之字形边缘石墨烯纳米带（ZGNR）的热电输运特性。通过采用BN对的共掺杂方案代替文献中报道的单个B和N原子，准束缚态的能量非常接近费米能级。由于来自准束缚态的反向散射，传输谷出现在费米能级附近，这导致两个自旋通道的传输斜率和塞贝克热功率较大。有趣的是，两个自旋通道的塞贝克热功率的符号相反，并且幅度几乎相等，可用于生成具有热梯度的纯自旋电流。更重要的是，热自旋电流对两个BN对之间的距离和掺杂结构的变化具有鲁棒性。这些发现表明了一个令人着迷的魅力。